For women age 75 and older, breast cancers detected by mammography were diagnosed at an earlier stage, thus reducing the rate of advanced cancers, according to a study published online August 5 in Radiology.

The findings suggest that mammography screening is beneficial for older women, said authors Judith A. Malmgren, PhD, affiliate assistant professor at the University of Washington’s School of Public Health and Community Medicine in Seattle, and colleagues.

“Downstaging of breast cancer is particularly critical among women 75 years and older because early-stage lesions are associated with improved prognosis and are potentially treatable without chemotherapy in a group with higher rates of comorbidity and general lack of resilience for such treatment,” they wrote.

The specifics of when and how often screening mammography should be used has been a point of contention, with the American Cancer Society supporting annual mammograms for women age 75 and older, while recommendations from the U.S. Preventive Services Task Force do not support mammography in this age group.

One major issue is the lack of evidence for mammography’s benefit in older women, which led Malmgren and colleagues to analyze the impact of mammography detection by studying data from an institutional registry that included more than 14,000 breast cancer cases. Of these, 1,600 patients were over age 75.

A majority (62 percent) of mammography-detected cases were early stage, while physician- and patient-detected cancer were more likely to be advanced stage and more likely to require mastectomies and chemotherapy. Treatment for mammography-detected invasive breast cancers, however, more often relied on lumpectomy and radiation.

Five-year disease-specific invasive cancer survival rates were 97 percent for mammography-detected cancers and 87 percent for patient- or physician-detected invasive cancers.

“When discussing mammography screening options after the age of 75, our results indicate that women should be informed of the possible benefit of a decreased need for aggressive treatment and better disease-specific survival associated with early detection with mammography,” wrote Malmgren and colleagues. “A woman’s personal health objectives, comorbid conditions, projected life expectancy, and tolerance for a possible false-positive result or treatment for breast cancer, if found, need to be taken into consideration.”